G. B. Lansbury
A5017734448- Astrophysical Phenomena and Observations
- Galaxies: Formation, Evolution, Phenomena
- Astrophysics and Cosmic Phenomena
- Gamma-ray bursts and supernovae
- Astronomy and Astrophysical Research
- Astronomical Observations and Instrumentation
- Particle Detector Development and Performance
- Pulsars and Gravitational Waves Research
- Astrophysics and Star Formation Studies
- Stellar, planetary, and galactic studies
- Geophysics and Gravity Measurements
- Particle physics theoretical and experimental studies
- Dark Matter and Cosmic Phenomena
- Solar and Space Plasma Dynamics
- Radio Astronomy Observations and Technology
- Calibration and Measurement Techniques
- Spacecraft and Cryogenic Technologies
- Scientific Research and Discoveries
- Advanced X-ray Imaging Techniques
- Science, Research, and Medicine
- Remote Sensing in Agriculture
- Medical Imaging Techniques and Applications
- Advanced Vision and Imaging
- History and Developments in Astronomy
- Adaptive optics and wavefront sensing
European Southern Observatory
2020-2024
University of Cambridge
2017-2020
Institute of Astronomy
2019
Durham University
2013-2018
Bridge University
2018
We present 1-7 GHz high-resolution radio imaging (VLA and e-MERLIN) spatially-resolved ionized gas kinematics for ten z<0.2 type~2 `obscured' quasars (log [L(AGN)/(erg/s)]>~45) with moderate luminosities [L(1.4GHz)/(W/Hz)]=23.3-24.4). These targets were selected to have known outflows based on broad [OIII] emission-line components (FWHM~800-1800 km/s). Although `radio-quiet' not `radio AGN' by many traditional criteria, we show that nine of the targets, star formation likely accounts <~10...
ABSTRACT We present a new metric that uses the spectral curvature (SC) above 10 keV to identify Compton-thick active galactic nuclei (AGNs) in low-quality Swift /Burst Alert Telescope (BAT) X-ray data. Using NuSTAR , we observe nine high SC-selected AGNs. find high-sensitivity spectra show majority are (78% or 7/9) and remaining two nearly ( N H ≃ (5–8) × 23 cm −2 ). SC BAT measurements consistent, suggesting this technique can be applied future telescopes. tested method on well-known AGNs...
We report on a NuSTAR and XMM-Newton program that has observed sample of three extremely luminous, heavily obscured WISE-selected AGN at z~2 in broad X-ray band (0.1 - 79 keV). The parent sample, selected to be faint or undetected the WISE 3.4um (W1) 4.6um (W2) bands but bright 12um (W3) 22um (W4), are rare, with only ~1000 so-called W1W2-dropouts across extragalactic sky. Optical spectroscopy reveals typical redshifts for this population, implying rest-frame mid-IR luminosities L(6um)~6e46...
The AllWISE processing pipeline has measured motions for all objects detected on Wide-field Infrared Survey Explorer (WISE) images taken between 2010 January and 2011 February. In this paper, we discuss new capabilities made to the software in order make motion measurements possible, characterize resulting data products use by future researchers. Using a stringent set of selection criteria, find 22,445 that have significant motions, which 3525 can be independently confirmed from earlier Two...
We present X-ray spectral analyses for three Seyfert 2 active galactic nuclei, NGC 424, 1320, and IC 2560, observed by NuSTAR in the 3-79 keV band. The high quality hard spectra allow detailed modeling of Compton reflection component first time these sources. Using quasi-simultaneous Swift/XRT data, as well archival XMM-Newton we find that all nuclei are obscured Compton-thick material with column densities excess ~5 x $10^{24}$ cm$^{-2}$, their above 3 dominated intrinsic continuum on...
We present a study of luminous, z=0.15, type-2 quasar (log [L([OIII])/(erg/s)]=42.8) from the Quasar Feedback Survey. It is classified as 'radio-quiet' [L(1.4 GHz)/(W/Hz)]=23.8); however, radio imaging reveals ~1 kpc low-power jets [Pjet/(erg/s)]=44) inclined into plane galaxy disk. combine MUSE and ALMA observations to map stellar kinematics ionised molecular gas properties. The are seen drive galaxy-wide bi-conical turbulent outflows, reaching W80 = 1000-1300 km/s, in phase (traced via...
We use the AllWISE Data Release to continue our search for WISE-detected motions. In this paper, we publish another 27,846 motion objects, bringing total number 48,000 when objects found during original survey are included. list, along with lists of confirmed WISE-based from recent papers by Luhman and Schneider et al. candidate paper Gagne widely separated, common-proper-motion systems. identify 1,039 such All further analyzed using color-color color-mag plots provide possible...
We report on the first ten identifications of sources serendipitously detected by NuSTAR to provide sensitive census cosmic X-ray background (CXB) source population at >10 keV. find that these NuSTAR-detected are ~100x fainter than those previously keV and have a broad range in redshift luminosity (z=0.020-2.923 L_10-40 keV~4x10^{41}-5x10^{45} erg/s); median z~0.7 keV~3x10^{44} erg/s, respectively. characterize basis broad-band ~0.5-32 spectroscopy, optical ultraviolet-to-mid-infrared SED...
We present a broadband (∼0.5–79 keV) spectral and temporal analysis of multiple NuSTAR observations combined with archival Suzaku Chandra data NGC 4945, the brightest extragalactic source at 100 keV. observe hard X-ray (>10 flux variability, variations factor two on timescales 20 ks. A variable primary continuum dominates high-energy spectrum in all states, while reflected/scattered that E <10 keV stays approximately constant. From modeling complex reflection/transmission spectrum, we derive...
We present Nustar 3-40 keV observations of the optically selected Type 2 quasar (QSO2) SDSS J1034+6001 or Mrk 34. The high-quality hard X-ray spectrum and archival XMM-Newton data can be fitted self-consistently with a reflection-dominated continuum strong Fe Kalpha fluorescence line equivalent-width >1 keV. Prior spectral fitting below 10 showed source to consistent being obscured by Compton-thin column densities gas along line-of-sight, despite evidence for much higher columns from...
The intrinsic column density (NH) distribution of quasars is poorly known. At the high obscuration end quasar population and for redshifts z < 1, X-ray spectra can only be reliably characterized using broad-band measurements that extend to energies above 10 keV. Using hard observatory NuSTAR, along with archival Chandra XMM-Newton data, we study nine optically selected (from SDSS), candidate Compton-thick (NH > 1.5 × 1024 cm−2) type 2 (CTQSO2s); five new NuSTAR observations are reported...
ABSTRACT Hot dust-obscured galaxies (hot DOGs), selected from Wide-Field Infrared Survey Explorer ’s all-sky infrared survey, host some of the most powerful active galactic nuclei known and may represent an important stage in evolution galaxies. Most hot DOGs are located at <?CDATA $z\gt 1.5$?> , due part to a strong bias against identifying them lower redshift related selection criteria. We present new method that identifies 153 DOG candidates $z\sim 1$?> where they significantly brighter...
We present two NuSTAR observations of the local Seyfert 2 active galactic nucleus (AGN) and an ultraluminous X-ray source (ULX) candidate in NGC 5643. Together with archival data from Chandra, XMM-Newton Swift-BAT, we perform a high-quality broadband spectral analysis AGN over decades energy ($\sim$0.5-100 keV). Previous suggested that is obscured by Compton-thick (CT) column obscuring gas along our line-of-sight. However, lack $\gtrsim$ 10 keV observations, together presence nearby luminous...
ABSTRACT We use a sample of powerful $z\, \approx \, 0.1$ type 2 quasars (‘obscured’; log [LAGN/erg s$^{-1}]\, \gtrsim 45$), which host kpc-scale ionized outflows and jets, to identify possible signatures AGN feedback on the total molecular gas reservoirs their galaxies. Specifically, we present Atacama Pathfinder EXperiment (APEX) observations CO(2–1) transition for nine sources CO(6–5) subset three. find that majority our reside in starburst galaxies (average specific star formation rates...
The merger of two or more galaxies can enhance the inflow material from galactic scales into close environments Active Galactic Nuclei (AGN), obscuring and feeding supermassive black hole (SMBH). Both recent simulations observations AGN in mergers have confirmed that are related to strong nuclear obscuration. However, it is still unclear how obscuration evolves last phases process. We study a sample 60 Luminous Ultra-luminous IR (U/LIRGs) GOALS observed by NuSTAR. find fraction Compton-thick...
We present NuSTAR hard X-ray observations of three Type 2 quasars at z ≈ 0.4–0.5, optically selected from the Sloan Digital Sky Survey. Although show evidence for being heavily obscured, Compton-thick systems on basis 2–10 keV to [O iii] luminosity ratio and multiwavelength diagnostics, their absorbing column densities (NH) are poorly known. In this analysis, (1) we study emission >10 keV, where X-rays central black hole relatively unabsorbed, in order better constrain NH. (2) further...
Abstract We present the first full catalog and science results for Nuclear Spectroscopic Telescope Array (NuSTAR) serendipitous survey. The incorporates data taken during 40 months of NuSTAR operation, which provide ≈20 Ms effective exposure time over 331 fields, with an areal coverage 13 deg 2 , 497 sources detected in total 3–24 keV energy range. There are 276 spectroscopic redshifts classifications, largely resulting from our extensive campaign ground-based follow-up. characterize overall...
Hot dust-obscured galaxies (DOGs) are hyperluminous (L8–1000 μm > 1013 L⊙) infrared with extremely high (up to hundreds of K) dust temperatures. The sources powering both their luminosities and temperatures thought be deeply buried rapidly accreting supermassive black holes (SMBHs). DOGs could therefore represent a key evolutionary phase in which the SMBH growth peaks. X-ray observations can used study obscuration levels luminosities. In this work, we present properties 20 most luminous...
We present the first direct measurements of rest-frame 10-40 keV X-ray luminosity function (XLF) Active Galactic Nuclei (AGNs) based on a sample 94 sources at 0.1 < z <3, selected 8-24 energies from in NuSTAR extragalactic survey program. Our results are consistent with strong evolution AGN population seen prior, lower-energy studies XLF. However, different models intrinsic distribution absorption, which used to correct for selection biases, give significantly predictions total number our...
ABSTRACT We present the 3–8 keV and 8–24 number counts of active galactic nuclei (AGNs) identified in Nuclear Spectroscopic Telescope Array ( NuSTAR ) extragalactic surveys. has now resolved 33%–39% X-ray background band, directly identifying AGNs with obscuring columns up to <?CDATA $\sim {10}^{25}\,{\mathrm{cm}}^{-2}$?> . In softer band are general agreement those measured by XMM-Newton Chandra over flux range $5\times {10}^{-15}\,\lesssim $?> S (3–8 keV)/...
We identify sources with extremely hard X-ray spectra (i.e., photon indices of Gamma<0.6 in the 13 sq. deg. NuSTAR serendipitous survey, to search for most highly obscured AGNs detected at >10 keV. Eight extreme are identified, and we use data combination lower energy observations (from Chandra, Swift XRT, XMM-Newton) characterize broad-band (0.5-24 keV) spectra. find that all AGNs, including three robust Compton-thick (CT; N_H > 1.5e24 cm^-2) low redshift (z<0.1), a likely-CT AGN higher...
ABSTRACT We present the first results from Quasar Feedback Survey, a sample of 42 z &lt; 0.2, [O iii] luminous AGNs ( L[O III] &gt; 1042.1 ergs s−1) with moderate radio luminosities (i.e. L1.4GHz 1023.4 W Hz−1; median = 5.9 × 1023 Hz−1). Using high spatial resolution (∼0.3–1 arcsec), 1.5–6 GHz images Very Large Array, we find that 67 per cent have spatially extended features on ∼1–60 kpc scales. The sizes and morphologies suggest these may be lower luminosity versions compact,...
High redshift quasars ($z>5$) that also shine brightly at radio wavelengths are unique signposts of supermassive black hole activity in the early universe. However, bright sources $z\ge5$ extremely rare and therefore we have started a campaign to search for new high-$z$ by combining an optical dropout selection driven $g$, $r$, $z$ bands from Dark Energy Spectroscopic Instrument (DESI) Legacy Imaging Surveys with low-frequency observations LOFAR Two-metre Sky Survey (LoTSS). Currently, LoTSS...
Galaxy mergers and gas accretion from the cosmic web drove growth of galaxies their central black holes at early epochs. We report spectroscopic imaging a multiple merger event in most luminous known galaxy, WISE J224607.56-052634.9 (W2246-0526), dust-obscured quasar redshift 4.6, 1.3 Gyr after Big Bang. Far-infrared dust continuum observations show three galaxy companions around W2246-0526 with disturbed morphologies, connected by streams likely produced dynamical interaction. The detection...